Conventionally, there is known an electronic musical instrument for generating music sounds according to performer's operation. In general, such an instrument is modeled on, e.g., piano, and designed to be operated similarly to a natural piano instrument. Therefore, some level of skill is needed to play the instrument and a long time is required to acquire proficiency in playing it.
In recent years, however, there is a demand that a performer unfamiliar with operating a musical instrument should be permitted to play a piece of music. Also, there is a demand that not only a performer can enjoy playing music, but also many performers can participate in and achieve an ensemble performance.
To this end, there has been proposed in, for example, Japanese Laid-open Patent Publication No. 2000-276141, an electronic musical instrument enabling a plurality of users unfamiliar with playing a musical instrument to participate in playing music. With this electronic musical instrument, users are enabled to implement an ensemble performance by making some easy actions (such as waving their hands). However, in the case of an ensemble performance being performed by a plurality of users unfamiliar with musical instrument operation, a deviation in playing performance can occur between the users, which poses a problem.
To eliminate such a deviation in performance, a musical performance assisting apparatus has been proposed in which a deference in tempo between a user's performance and musical score data is detected and the detected difference is displayed on a musical score (see, for example, in Japanese Laid-open Patent Publication No. 2001-337675). Also, there has been proposed a musical performance display apparatus, in which a history of timing of model performance and a history of timing of user's performance are displayed on a display screen, thereby comprehensively showing a difference relative to the model performance (see, for example, Japanese Laid-open Publication No. 2002-91290).
The above described performance assisting apparatus and the performance display apparatus are adapted to display a deviation relative to musical score data or model performance (demonstrative performance). These apparatuses are for individual use by users for making progress in playing performance.
In a case where a plurality of users (participants) perform rehabilitation or other activity together, as described in the aforementioned Japanese Laid-open Patent Publication No. 2000-276141, they are often divided into groups each consisting of a predetermined number of users (about five users, for example) including a facilitator (guide) who guides other participants. In that case, each participant plays music in time with the facilitator's performance. With the performance assisting apparatus and the performance display apparatus, a deviation relative to musical score data or mechanical demonstrative performance can be displayed, however, a deviation relative to a human musical performance performed by a facilitator or other human guide cannot be displayed.
The object of the present invention is to provide an ensemble system enabling even a performer unfamiliar with operating a musical instrument to easily grasp a deviation of a performer's performance from a facilitator's performance.